The present invention relates to a disposable filter unit. More particularly, the invention is a filter unit wherein the reservoir for the liquid to be filtered and the receptacle for receiving the filtrate are formed as a unitary one piece unit.
Filtration units of the type described herein are used in a wide variety of laboratory applications. Consequently, it is desirable that the unit be in a sterile condition prior to use. U.S. Pat. No. 3,295,686 discloses such a disposable filter unit which eliminates many of the drawbacks of reusable filter units described as prior art in that patent.
A disposable filter unit according to U.S. Pat. No. 3,295,686 would consist of a reservoir for holding the liquid to be filtered, a separate receptacle for receiving the filtrate and a support member for holding the filter medium. These three components would be assembled as by welding to form a unitary structure. This construction required that the different components be provided with appropriate structure to permit the components to be fitted together and attached one to another. Moreover, in such construction, care had to be exercised in order to insure an air-tight seal about the filter medium so as to prevent leakage of air from the surrounding environment into the filtrate receptacle.
The present invention overcomes many of the drawbacks of prior art disposable filtration units by providing a one-piece molded unit which not only greatly reduces the manufacturing steps, but also provides a filtration unit wherein there is no possibility for leakage of air into the filtrate receptacle.